Asymptomatic Bacteriuria in the Elderly
Abstract: The aim of this thesis was to explore the features of asymptomatic bacteriuria (ASB) in elderly people living in the community, and to seek diagnostic tools to discriminate between ASB and symptomatic urinary tract infection (UTI).All men and women aged 80 and over living in an urban district of Falun, Sweden, were invited to participate. Urine samples were obtained together with information on symptoms and on health indicators. The same cohort was surveyed again after 6 and 18 months. Urinary cytokines were analysed in 16 patients with UTI, in 24 subjects with ASB and in 20 negative controls.ASB occurred at baseline in 19.0% of women and 9.4% of men, and was found at least once in 36.9% of women and in 20.2% of men. ASB in women was associated with reduced mobility and urge urinary incontinence. Of those with ASB at baseline, 60% still had bacteriuria at 6 and 18 months, but among those with repeated findings of ASB with E. coli, only 40% had the same bacterial strain after 18 months. In women, the risk of developing a UTI within 24 months was higher among those with ASB at baseline than in those without. Urinary levels of cytokines (CXCL1, CXCL8 and IL-6) and leukocyte esterase were higher in patients with UTI than in patients with ASB.There is convincing evidence that ASB is harmless and should not be treated with antibiotics. However, such treatment is still often given, thereby unnecessarily contributing to the increased number of bacteria resistant to common antibiotics. This study confirms the high prevalence of ASB in elderly people living in the community. In order not to be misled by a urinary test showing bacteria, it is important to restrict urinary testing for bacteria to patients where there is a suspicion of UTI. In elderly patients with diffuse symptoms or in patients who are unable to communicate their symptoms, further diagnostic help could possibly be obtained by evaluating the urinary levels of leukocyte esterase and/or IL-6.
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